package com.java.al.md5;

import java.applet.*;
import java.io.*;
import java.security.*;

public class HashFile {
    public static char[] hexChar = {'0', '1', '2', '3',
                                   '4', '5', '6', '7',
                                   '8', '9', 'a', 'b',
                                   'c', 'd', 'e', 'f'};
    public static void main(String[] args) throws
            Exception {
        String fileName = "c:/Test.txt";
        String hashType = "MD5";
        System.out.println(hashType + " == " +
                           getHash(fileName, hashType));
        hashType = "SHA1";
        System.out.println(hashType + " == " +
                           getHash(fileName, hashType));
        hashType = "SHA-256";
        System.out.println(hashType + " == " +
                           getHash(fileName, hashType));
        hashType = "SHA-384";
        System.out.println(hashType + " == " +
                           getHash(fileName, hashType));
        hashType = "SHA-512";
        System.out.println(hashType + " == " +
                           getHash(fileName, hashType));

    }

    public static String getHash(String fileName, String hashType) throws
            Exception {
        InputStream fis;
        fis = new FileInputStream(fileName);
        byte[] buffer = new byte[1024];
        MessageDigest md5 = MessageDigest.getInstance(hashType);
        int numRead = 0;
        while ((numRead = fis.read(buffer)) > 0) {
            md5.update(buffer, 0, numRead);
        }
        fis.close();
        return toHexString(md5.digest());
    }

    public static String toHexString(byte[] b) {
        StringBuilder sb = new StringBuilder(b.length * 2);
        for (int i = 0; i < b.length; i++) {
            sb.append(hexChar[(b[i] & 0xf0) >>> 4]);
            sb.append(hexChar[b[i] & 0x0f]);
        }
        return sb.toString();
    }
}